1. Field of the Invention
This invention relates to pre-gapped breaker point assemblies for distributors of internal combustion engines.
2. The Prior Art
Spark plug systems for internal combustion engines incorporate a distributor apparatus to suitably direct electrical energy to the appropriate spark plug to produce an electrical spark which ingites the fuel/air mixture in the cylinder. A significant aspect of accurately timing the spark initiation is in the gap distance by which the contact points of a mechanical distributor system separate during operation.
Mechanical breaker point assemblies generally include a spring-biased, oscillatory breaker arm with a movable contact mounted on the end thereof. A stationary contact is mounted on a stationary bracket and placed to intercept the movable contact. The breaker arm and the bracket are both mounted on what is commonly referred to as a breaker plate. The breaker plate is adapted to be secured in the distributor of an internal combustion engine.
The oscillatory breaker arm includes a cam follower which is resiliently urged against an engine-rotated cam. Rotation of the cam imparts an oscillatory movement to the breaker arm. The oscillatory movement of the breaker arm provides a sequential contact between the movable contact and the stationary contact. Conventional mechanical distributiors are configurated such that the maximum gap distance between contact points is obtained coincident with the cam follower at a high point or lobe of the cam. Conventional breaker point assemblies also incorporate adjustment means for suitably positioning the breaker point assembly with respect to the distributor and the cam so as to obtain the appropriate gap distance between the fixed and the movable contact point when the cam follower is at a high point on the cam.
It is common knowledge that the distributor contact points eventually become worn and require replacement. Replacement of worn contact points has historically been accomplished by replacement of the entire breaker point assembly in the distributor, including the breaker arm and the stationary contact bracket. Replacement is accomplished by careful adjustment to obtain the appropriate gap distance between the contact points. Historically, this adjustment procedure generally requires the services of an experienced mechanic since it is a relatively difficult task for the layman.
Pre-gapped breaker point assemblies are dislcosed and claimed in each of my previous patents, U.S. Pat. No. 3,833,777, issued Sept. 3, 1974, for PRE-GAPPED BREAKER POINT ASSEMBLIES and U.S. Pat. No. 3,956,602, issued Feb. 12, 1975, for PRE-GAPPED BREAKER ASSEMBLY. Each of these patents relate to spacing block apparatus wherein the spacing block is mounted upon the stationary bracket.
However, it is currently believed that it would be an improvement in the art to provide a spacing block assembly mounted upon the oscillatory breaker arm. This spacing block assembly would accommodate setting the correct gap distance for the contact points with a minimal amount of subsequent adjustments required after the replacement breaker point assembly has been placed in the distributor.